Just posted this in another thread, but since that thread is long and is not going to be read as much, thought I would start a new thread. This may be utterly wrong and I may regret posting it, because I don't know squat about mechanical stuff, but here goes:
I'm not a mechanic, and I don't know a lot, but I was talking to a MINI service guy and I asked him what I have been asking a lot of people... what is the difference between the straight Cooper engine and the N14, that the N14 gives this trouble and the straight Cooper (N12) doesn't? Why do the timing chain/cold start threads have so many failing turbo MINIs and no straight Cooper engines failing? What is the difference??

From what he said (and he couldn't say much, of course!) it almost sounds like the turbo version has more oil pulled up into the engine when starting, because it goes up into the turbo **as well as* into the engine itself. So, with the same oil capacity (4.4 quarts or so?) the turbo engine immediately moves more oil up into the system than the non turbo does, thus dropping the oil level further, and leaving less for that timing chain tensioner. Now, he couldn't say that, it is my guess, but he was talking about how the oil is required for the turbo as well as the regular engine parts... and how much pressure that oil is under to move it through the system. That MIGHT be why dealerships tend to overfill... instead of saying that there should be more oil in the system than it indicates. ONLY MY GUESS.... so what do you guys think, who have actually worked on these engines? Might the turbo engines require a higher oil level, but were not designed to have it?

And of course cold start rattling is associated with low oil/sludgy oil, and wearing of the chain and tensioner.

He also confirmed that the heat from the turbo tends to sludge the oil over time, and that the engine also burns oil as anyone could guess who has had to pay for the walnut shell blasting.

These issues are not going to happen in the straight engine....

Loving my straight Coopers! __________________

 

if you take a turbo oil feed line and fill it with oil, i doubt it holds more than 2-3 oz of oil so i discount that theory

however

i have a friend that has an independant auto repair shop

he has done almost 100 timing chains and he says almost all of them had the oil galley that feeds the timing chain almost completely blocked by sludge

turns out those same cars had the oil changed only at the mini recommended interval, ie 15,000 miles or more

he has numerous other customers with many miles that do 5,000 mile or less oil changes and they have no timing chain issues

he will now only work on minis if the owner agrees to 5,000 mile or less oil change intervals

as to burning oil, i run my oil level at the 1/2 point from full and burn no oil between changes at 4,000 miles ... when i change the oil i only fill to the 1/2 mark, not to full

if i fill to full, the car will burn 1/2 qt in 200-300 miles until it gets to the 1/2 mark and then no more oil is consumed

my dad's cms all4 does exactly the same with the oil ... run at 1/2 and consume no oil

scott

edit:

i talked to a mechanic (not the service writer) at the dealer about running the oil at 1/2

he said "mini recommends only adding oil when the level falls to the "add" mark and to not continously top up the oil"

 

Scott has some good info there.

In many cases, those buying a late model Turbo S came in from driving a non-turbo equipped vehicle, thus unaware of a Turbo's inherent ability to consume engine oil.

And IMO recommending oil change intervals at 15K was ludicrous. This was also coupled with a dip stick design which is very difficult to read. This is why about 3 years ago I sent an email to Kellen at Craven Speed to make up some sticks for the R56.

That said, those not used to having oil consumption in their previous cars rarely checked their oil levels in their MINI-S between the 15K mile intervals like they thought MINI was using some sort of "magic" oil ?.....And some of those who did check may have been seeing false dip stick readings as well. These low engine oil levels resulted in the failure to properly cool/lubricate the timing chain causing the chain deflection (stretch) and subsequent failures.

 

I totally agree on all of that, but there has to be another reason for the difference too. There has to be. Plenty of straight Coopers get neglected too, don't get oil changes, they get bought by people who are even less car savvy. Actually, many more MCs are sold than MCSs. Yet of all the mechanics I've asked, not one has had to replace timing chains on MCs. So there is something more about the turbos that is causing this. And there have been people who did take care of their oil, who still got the problem.
So the turbo oil feeder line only holds a few ounces? Dang. I was so excited to think that might be it. And Scott, if you keep yours a half quart low and it's fine, how low is 'low'? Is the problem just sludge? Is the feeder line for the tensioner too small in diameter?

 

Have to factor in the torque parameters and stresses of the S engine on those parts vs the Non-S. Also, one has to ask, why does the new N18's S engine use the same timing chain from the early R56 NON S models ? Maybe the tensile strength of the prior S models chain was not up for the job ?

The feeder line probably holds less than than oz .

I meet folks all the time who say they regularly perform oil level checks only to find that when the oil level is actually checked it's 3 and even 4 qts low.....and/or can't understand why a base model MC has drive-ability/idle issues at stop lights only to find out that under more thorough questioning they have been pumping 89 octane. just because they say "they take care of" or "do what they should', doesn't necessarily mean they do...

The Peugeot engine takes 4.7 litre or 4.5 qts.

 

Given all the people who have suffered timing chain/tensioner failures even though they were using oil change intervals anywhere between 5,000 and 10,000 miles, any theory that tries to relate the interval to the failures is unlikely to be correct.

 

You are assuming they did those oil changes since you did not perform them correct ?

VW's standard is a quart per 1000 miles....that could possibly translate to losing 4 qts before a 5K mile oil change. That is what I was told when I purchased a brand new GTi 16v in 92.

 

Nearly backwards. 4.5L = 4.76qt

Keith

 

Is the turbo oil feeder line somehow ahead of the timing chain tensioner, such that a clogged feeder line would interrupt the supply of oil to the tensioner? That mechanic said that they commonly see clogged turbo oil lines during timing chain failures.
The new N18s use the same chain as the older straight engines? Now, that's interesting!

 

An ounce of oil isn't very much. A cup holds eight ounces. That feeder line must be very narrow if it only carries a couple of ounces into the turbo. And how much oil is inside the turbo? With the high heat of the turbo, and such little oil to absorb that heat, is there an oil cooler inline with it? Seems like that would sure take a toll on the engine oil!

 

there is another factor besides frequency ...

the type of oil used

mini specs oils that meet ACEA A3/B3

these are full synthetic with "long life" additive packages and high sludge resistance from high temperature exposure

btw, i do use the Craven dipstick

gRay, better check your math, 1 liter = 1.06 quarts

the dealer mechanic told me 4.4 quarts is the refill quantity with a filter change, so that is not necessarily the quantity the engine holds as not all the oil is drained

look at the drain pan bung welded to the inside of the oil pan



somr oil remains in the pan

scott

 

the turbo holds little oil but is cooled by water also

i always drive very "easy" the last couple of miles before my destination AND let the engine idle for at least 1 minute before turning it off

this allows the turbo to cool

driving this way, my fan does not run after shutdown, even during the summer but the aux wayer pump still runs if the temp is over 90F or so

scott

 

Please share with us those that have done oil changes with proper oil/filter every 3-5k miles SINCE THE CAR WAS NEW and has still had timing chain issues. I would like to inquire some more about those specific failures. Thank you.

 

 

 

If we don't get a lot if replies, omgjcw, I'll go back through those threads and pull and paste the most credible of the posters who said that they were diligent about their oil changes and levels. :-). That would certainly be interesting.

 

The most important thing is the claims accuracy if these were done since the car was new. If they weren't, it's really pointless to lay the claim. Most of the damage can occur with the oil level reaching a low point one time and for the first time. The condition can start as a minor cracked or broken guide and not be noticed by the customer for a long time until the guide says "enough is enough". Unless the owner is original owner and lays claim to this oil change interval, the point is invalid. But if you do find one, I would like to ask some questions about their experience. And no, not demeaning questions. I have valid questions about valid cases of failure. Thank you.

 

i am working on just that

11,000 miles and 3 oil/filter changes so far, #4 due at 12,000

i use mobile1 0W40, the dealer uses the 5W30 mini oil

give me a couple more years

scott

 

Scott, not a bad thing, but more importantly than changing the oil is simply being aware more often where the oil level lies. The point to my response has little to no bearing on actually having the engine oil changed that often, but more so that the owner did in fact check and correct the engine oil level at least every 3k miles. Changing the oil is mearly an owner preference. I assure you, proper long-life full synthetic oil such as the MINI oil or long life Mobil 1 will last every bit of 15k miles. Oil is changed not because it breaks down, but because it picks up particulates and contaminates from the engine and condensation. Glad you love maintaining your MINI, but I would recommend saving some money, cutting down by half on the oil changes and use long-life oil such as the MINI oil. And definitely use MINI oil filter. I have seen oil pressure issues with aftermarket filters. There are other MINI approved oils listed on MINIUSA.com. Any of these are just fine. Just check the oil level every so often.

 

45k miles and oil changed every 5k. No noise on start up ever and my car uses no oil. I've generally used Castrol Syntech 5w30. I swear by my frequency of oil changes, but there are those here on this forum that will say wait until the maintenance reminder says to change it. To each his own.

 

Contrary to what the OP indicated, there have been N12 timing chain/guide failures. They just are less frequent because of most of the reasons already noted:

Much fewer N12s than N14s on the road

N12 does not contaminate oil nearly as rapidly as N14

N12s do not tend to lose oil, so they are much less frequently operated at ridiculously low oil levels as is typical of N14s going 15K between oil changes where owner rarely checks/adds oil

Sooty oil can restrict oil flow through the tiny oil hole in the tensioner. Combine that with very low oil levels and the tensioner does not pump up as quickly on cold starts. Consequently, the chain drags on the nylon guides longer and causes more wear than if it was better controlled.

My N12 has never needed oil to be added. I am at 39K and change oil and filter every 5K.

The chain slack on a new N12 is 63.9 mm. At 28K my N12 had 65.54 mm. I expect it to be around 67.5 mm at 43K when I plan to check it again. At that time, I plan to install the "long" tensioner. I hope BMW has a recall in place by then. If not, I will try to get my dealer to do a "system" replacement just before the 50K warranty expires.

I believe an Accusump will address the problem because the tensioner will always be fully pumped up at every startup.

However, the timing chain system is just a poor design. Look at the chain cam drive layout on say, a 2005 4 cyl Toyota Camry (DOHC), for comparison. I know several of these that have gone 500K without a timing chain service or system failure.

An Accusump, I believe will get either an N12 or N14 timing chain "system" to last to 100K as long as the oil is consistently clean and kept up to level. However, that is still really not acceptable for a chain system, but at least would bring it in line with typical timing belt service intervals/cost.

(I just personally did the 100K TB service on my wife's diesel Jeep. It was $800 in parts. Dealer would have charged $2400.)

DOC

 

Robert, the way I put it to everyone who asks......it never hurts to change oil more often. So if it makes anyone feel better to change it more often, whether it needs to be or not.....then absolutely do it. That's what I do. I know it won't hurt to wait. But it gives me the warm and fuzzies to change it a little more frequently so I do it. It's my money, so who cares? Glad to hear your well running noise free N14 with proper service sir!!

 

Thanks Ked!

Yeah my math can be off after just 3 hrs sleep and then working here since 2:30 AM this morning

 

Question

Does anyone pour a extra 1-2 bottles of fresh 5w30 oil inbetween the 5000 miles oil change?

 

No - but I check it weekly and top it off when needed.